With winds reaching supersonic speeds of 9,000 miles per hour and temperatures up to 1,400 degrees Kelvin (about 2,000 degrees Fahrenheit), three planets of another galaxy have piqued the interest of UW researchers.

Nick Cowan, a UW graduate student studying astronomy, Eric Agol, a UW assistant professor of astronomy and David Charbonneau, an astrophysicist from Harvard, recently wrote a scholarly article giving reasons for why the temperature throughout these planets seem to be fairly uniform.

"[We're] trying to see if dayside temperature is different from nightside temperature," Cowan said. "[The] question is how hot the nightside is going to be ... What we found is that their nightside is probably also really, really hot."

The three planets studied are 51 Pegasi, HD 179949b — and HD 209458b — all ranging from 50 - 150 light-years away.

The planets are Jupiter-sized, gaseous and 10 times closer to their sun than Mercury is to ours, giving them the nickname "hot Jupiters."

Using NASA's Spitzer Space Telescope, Cowan and colleagues estimated the varying temperatures at eight different points in the planets' orbits by counting photons using infrared cameras.

This process can be extremely tedious.

"It's like trying to see a firefly in a headlight," Cowan said. "Out of 1,000 photons that you detect, 999 are coming from the star and one from the planet, which is why this made it so difficult."

To count photons, a charge-coupled device (CCD) records how much light falls on the chips in a certain amount of time and transfers this data to a computer.

"It's basically a digital camera on steroids," said Mark Claire, an astronomy graduate student.

Albedo, the ratio of light reflected to light received, is exhibited at different levels at different points in time, with more light when the dayside is facing the planet and less light when the nightside faces it. When looking at the Jupiters, the variations in brightness at different points of orbit seem to be relatively constant with small variations.

"Can't say dayside and nightside are exactly the same, but close," Cowan said. "As far as the nightside, ... best guess is 1,000 to 1,200 Kelvin, ... [a] couple hundred degrees cooler [than dayside]."

This difference is less significant than it seems given the extreme temperatures on the planets, Cowan said.

The planets are also tidally locked, meaning one side of the planet is continually facing the sun. The reason for this is the close proximity the planets have to the sun. The case is similar to that of the Earth and moon.

"Basically, the Earth causes tides on the moon as well as slows down the moon's rotation," Cowan said. "You always see the same side on the moon."

The same principle applies to these hot Jupiters. Yet it is harder to define the rotation of a gas planet since the whole planet isn't moving as a fixed body.

To keep the temperature uniform throughout the whole planet, some kind of force (wind, for example) is needed to distribute the heat evenly. Being in close proximity to the sun, the winds are faster than those on the gas planets in Earth's galaxy because there is more energy to play with, Cowan said.

Though these planets are interesting to study, they're not suitable for living.

"I think hot Jupiters are really cool," Claire said. "But I wouldn't want to live on one."

More than 200 Jupiter-sized planets or larger have been discovered to date. With advancement in technology, discoveries of smaller planets may start to appear.

"It's really exciting that we're starting to figure out [information] about extra solar planets," said Eric Hilton, an astronomy graduate student. "Everything so far has been indirect evidence ... the planets that we can detect at this point probably aren't interesting for [finding] life but for how planets are formed ... which we knew less about than we though."

Reach reporter Doris Wu at news@thedaily.washington.edu.